1. Technical Field
The present invention relates to a medium transport device, a recording apparatus, and a lubricity maintaining method to be used for a rotation shaft and a bearing of the rotation shaft of the medium transport device.
2. Related Art
In the related art, medium transport devices each of which includes a rotation shaft and a bearing of the rotation shaft which enable transport of media using rotation have been used. In such medium transport devices, a lubricant such as grease is applied to a contact portion of a rotation shaft with a bearing of the rotation shaft in order to maintain lubricity between the rotation shaft and the bearing of the rotation shaft.
In contrast, in many machine tools, each of which includes a rotation shaft and a bearing of the rotation shaft, have been used, and a lubricant is applied to a contact portion of the rotation shaft with the bearing of the rotation shaft. Since such a lubricant applied to a contact portion of a rotation shaft with a bearing of the rotation shaft is subjected to time degradation due to incorporation of impurities, oxidation, or the like, a supply mechanism that supplies a fresh lubricant to the contact portion is used as disclosed in, for example, JP-A-10-58278, JP-A-10-184705, International Publication No. WO01/31215, JP-A-2011-241953, JP-UM-A5-92538, and JP-A-2008-291970.
However, it is difficult to combine a small and complicated lubricant supply mechanism with a rotation shaft and a bearing of the rotation shaft in a medium transport device. For this reason, it is difficult to combine a complicated supply mechanism that supplies a lubricant to a contact portion of a rotation shaft with a bearing of the rotation shaft with such a medium transport device as disclosed in JP-A-10-58278, JP-A-10-184705, International Publication No. WO01/31215, JP-A-2011-241953, JP-UM-A-5-92538, and JP-A-2008-291970.
For this reason, it was difficult to maintain lubricity between a rotation shaft and a bearing of the rotation shaft in a medium transport device of the related art.